1. Field of the Invention
The present invention relates to a current controller for controlling a current caused to flow through an inductive load such as a solenoid.
2. Description of the Related Art
As described in JP 3,030,076 B for example, a conventional current controller is configured so that an output signal of a smoothing means and an output signal of a holding means are compared with each other, and ON/OFF control of a switching means for controlling a driving current caused to flow through an electromagnet is carried out on the basis of the comparison results, whereby even if a power supply voltage or a coil resistance of an actuator is changed, a fixed mean current can be obtained.
However, in the conventional current controller, since a peak holding amplifier as the smoothing means detects a current caused to flow through a coil to thereby correct a time period of an ON state of a power transistor as the switching means, the peak holding amplifier can not accurately detect the current caused to flow through the coil in correspondence to a change in ratio between a turn-ON time period and a turn-OFF time period of a power transistor. Consequently, there is a fixed limit to the accuracy for current control.